The permit had been approved for a Maryland-based KKK group, the Confederate White Knights of the Ku Klux Klan, for a Saturday gathering.

Park officials had defended granting the permit, saying they have a responsibility to make the land available for citizens to exercise their right to freedom of speech, even if the views expressed are contrary to those of most Americans.

The group held a membership rally last month at the Antietam National Battlefield near Sharpsburg, Md., where thousands died in a Civil War clash that set the stage for the Emancipation Proclamation.